1. Field of the Invention
The embodiments of the present invention relate to a semiconductor laser array and, more particularly, to a structure for a semiconductor laser array of a phase synchronized type.
2. Description of the Prior Art
A practical maximum output of a single semiconductor element is about 50 mW. A semiconductor laser array, which has a plurality of semiconductors that are aligned on a single semiconductor substrate, is proposed in order to create a high power semiconductor laser.
FIGS. 1(A) and 1(B) show the beam intensity distribution and the index distribution , respectively, of the conventional semiconductor laser array. Generally, an oscillation mode can be selected so that each guide is synchronized with a 0.degree.-phase different to each other guide in a semiconductor laser array. Whereby a plurality of index guide semiconductor lasers may be coupled to each other through, for example, Y-shaped division guides. However, in the conventional device, the beam intensity distribution on the mirror surface is not uniform as shown in FIG. 1(A). In particular, the guide of the central portion emits greater power beam than the guide of the end portion. Accordingly, the practical maximum power of the conventional semiconductor laser array does not become N-times greater than semiconductor laser even when an N-number of semiconductor lasers are aligned on a single semiconductor substrate. The number of the semiconductor lasers on the substrate should be maintained as low as possible because the driving current increases as the number of the semiconductor lasers increase. The driving current creates a heat problem, and the operating life period of the semiconductor laser device is adversely affected.